// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ui/display/util/x11/edid_parser_x11.h"

#include <X11/Xatom.h>
#include <X11/Xlib.h>
#include <X11/extensions/Xrandr.h>

#include "base/strings/string_util.h"
#include "ui/display/util/edid_parser.h"
#include "ui/gfx/x/x11_types.h"

namespace ui {

namespace {

    bool IsRandRAvailable()
    {
        int randr_version_major = 0;
        int randr_version_minor = 0;
        static bool is_randr_available = XRRQueryVersion(
            gfx::GetXDisplay(), &randr_version_major, &randr_version_minor);
        return is_randr_available;
    }

    // Get the EDID data from the |output| and stores to |edid|.
    // Returns true if EDID property is successfully obtained. Otherwise returns
    // false and does not touch |edid|.
    bool GetEDIDProperty(XID output, std::vector<uint8_t>* edid)
    {
        if (!IsRandRAvailable())
            return false;

        Display* display = gfx::GetXDisplay();

        static Atom edid_property = XInternAtom(
            gfx::GetXDisplay(),
            RR_PROPERTY_RANDR_EDID, false);

        bool has_edid_property = false;
        int num_properties = 0;
        gfx::XScopedPtr<Atom[]> properties(
            XRRListOutputProperties(display, output, &num_properties));
        for (int i = 0; i < num_properties; ++i) {
            if (properties[i] == edid_property) {
                has_edid_property = true;
                break;
            }
        }
        if (!has_edid_property)
            return false;

        Atom actual_type;
        int actual_format;
        unsigned long bytes_after;
        unsigned long nitems = 0;
        unsigned char* prop = nullptr;
        XRRGetOutputProperty(display,
            output,
            edid_property,
            0, // offset
            128, // length
            false, // _delete
            false, // pending
            AnyPropertyType, // req_type
            &actual_type,
            &actual_format,
            &nitems,
            &bytes_after,
            &prop);
        DCHECK_EQ(XA_INTEGER, actual_type);
        DCHECK_EQ(8, actual_format);
        edid->assign(prop, prop + nitems);
        XFree(prop);
        return true;
    }

} // namespace

EDIDParserX11::EDIDParserX11(XID output_id)
    : output_id_(output_id)
{
    GetEDIDProperty(output_id_, &edid_);
}

EDIDParserX11::~EDIDParserX11()
{
}

bool EDIDParserX11::GetDisplayId(uint8_t index, int64_t* out_display_id) const
{
    if (edid_.empty())
        return false;

    return GetDisplayIdFromEDID(edid_, index, out_display_id, nullptr);
}

std::string EDIDParserX11::GetDisplayName() const
{
    std::string display_name;
    ParseOutputDeviceData(edid_, nullptr, nullptr, &display_name, nullptr,
        nullptr);
    return display_name;
}

bool EDIDParserX11::GetOutputOverscanFlag(bool* out_flag) const
{
    if (edid_.empty())
        return false;

    return ParseOutputOverscanFlag(edid_, out_flag);
}

} // namespace ui
